# WebHelpers / webhelpers / misc.py

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128``` ```"""Helpers that are neither text, numeric, container, or date. """ import itertools def all(seq, pred=None): """Is ``pred(elm)`` true for all elements? With the default predicate, this is the same as Python 2.5's ``all()`` function; i.e., it returns true if all elements are true. >>> all(["A", "B"]) True >>> all(["A", ""]) False >>> all(["", ""]) False >>> all(["A", "B", "C"], lambda x: x <= "C") True >>> all(["A", "B", "C"], lambda x: x < "C") False From recipe in itertools docs. """ for elm in itertools.ifilterfalse(pred, seq): return False return True def any(seq, pred=None): """Is ``pred(elm)`` is true for any element? With the default predicate, this is the same as Python 2.5's ``any()`` function; i.e., it returns true if any element is true. >>> any(["A", "B"]) True >>> any(["A", ""]) True >>> any(["", ""]) False >>> any(["A", "B", "C"], lambda x: x <= "C") True >>> any(["A", "B", "C"], lambda x: x < "C") True From recipe in itertools docs. """ for elm in itertools.ifilter(pred, seq): return True return False def no(seq, pred=None): """Is ``pred(elm)`` false for all elements? With the default predicate, this returns true if all elements are false. >>> no(["A", "B"]) False >>> no(["A", ""]) False >>> no(["", ""]) True >>> no(["A", "B", "C"], lambda x: x <= "C") False >>> no(["X", "Y", "Z"], lambda x: x <="C") True From recipe in itertools docs. """ for elm in itertools.ifilter(pred, seq): return False return True def count_true(seq, pred=lambda x: x): """How many elements is ``pred(elm)`` true for? With the default predicate, this counts the number of true elements. >>> count_true([1, 2, 0, "A", ""]) 3 >>> count_true([1, "A", 2], lambda x: isinstance(x, int)) 2 This is equivalent to the ``itertools.quantify`` recipe, which I couldn't get to work. """ ret = 0 for x in seq: if pred(x): ret += 1 return ret def convert_or_none(value, type_): """Return the value converted to the type, or None if error. ``type_`` may be a Python type or any function taking one argument. >>> print convert_or_none("5", int) 5 >>> print convert_or_none("A", int) None """ try: return type_(value) except Exception: return None class DeclarativeException(Exception): """A simpler way to define an exception with a fixed message. Example: >>> class MyException(DeclarativeException): ... message="can't frob the bar when foo is enabled" ... >>> try: ... raise MyException() ... except Exception, e: ... print e ... can't frob the bar when foo is enabled """ message="" def __init__(self, message=None): Exception.__init__(self, message or self.message) if __name__ == "__main__": import doctest doctest.testmod() ```